Adjustable pressure relief valve



Oct. 9, 1.945.'y E. w. CLI-:MENTS E 2,386,293

rADJUSTABLE PRESSURE RELIEF VALVE Filed 2mg. 12, 1942 lll NVENTOR ERNEST M. CLEMENTJ `ATTORNEY Patented Oct. 9, 1945 ADJUS TABLE PRE S SURE 'RELIEF Ernest `W. Clements, Kansas City, Kans., as-

vsignor to Andrew A. Kramer, Kansas "City,

Application August-12, 1942,'Seria1No. 4543551 (CLIM-53) 3 Claims.

invention relates :to adjustable Vpressure re- 'lief` valves, and more particularly to'such 1a `valve adapted for controlling maximum pressures .in a respirator. rIhis application is arcontinuation-inlpart -of my .application kSerial No. 319,091, ri'lled February 15, 1940, for patent on Respirator.

It is a purpose of my invention yto provide a val-ve for controlling the maximum pressure in achamberthat is :connectedwithpumping means for alternately :increasing .and :decreasing the pressure therein, whichisrsimple inconstruction and whichc'ancb'eadjusted readily and -Will re- ?main 1in-adjusted `positionywithout any :possibility o'f Tthe :same :becoming vout .of adjustment, `the djustingmeans being ,of a self-locking ,charac- ,It is .a .particular `purpose of :my invention to provide a valve of the above mentioned rcharacter, that comprises a iiapv valve membenvwhich :is `.provided with means yfor normally opening the same to relieve the pressure withinachamber at a -denite maximum pressure, this Abeing eaccom- Lplished 4by means of a Weight Aprovided on said -rlap valve, but which .is .adapted to beadjusted :so as to clampgthe valve member down on `its seat, fso as to -fprevent opening A,thereof-'atsaid ,maximum pressure.

Itis a further :purpose of `my-invention `to provide 2a valve ofthe above mentioned character, vWhich has means .-foradjustingthe same, so that Ltheamount of opening of -the valve, after fthe maximum .pressure has been reached :that Jopens the same,rcan be adjusted to control the r-ate of discharge of l air from the chamber through-said pressure relief valve, to thereby control the pressure `rise during the pressure increasing strokerof the pumping meansin a desired manner to imitate the breathing action of the ypatient within a vrespirator chamber, by means of the pressure changes therein, .more accurately than would otherwise be possible. The valve can thus bead- -justed `to prevent sudden pressure drops upon opening of the valve or can-be adjusted yso that fthe'pressure will increase slightly'after the Avalve .opensyor that the pressure willrincreaseconsiderably after the valve opens, as lmay .be desired for theparticular patient in therespirator.

Itis a 4particular purposeof my invention to .provide ya valve-of the `above mentionedcharac- .terpthat is-simple in construction,employs a very smallfnumber of parts, and isso constructedxand `arranged. that the :operating parts are readily visible toran observer,so-thatiif any lackof propfer? functioning of the valve exists. itl can be Vreadily noted. 'Furthermore my improved valve is so constructed that it is sturdy and that lthe lvalve member itself is protected from `possible damage orinterference With'the operation'thereof byfoutlside means, and in which the Weightficomprises a plate-like member 'th-at also acts as a .bearing plate for a screw-threaded adjusting member for clamping the valve Yto its seat and'for engagement with said screw-threadedmember when the;same serves as an adjustable stop for limiting, lthe opening movement of the valve.

Other objects and advantages of my-invention will appear as the description of the drawing proceeds. I desire tohave it understood, however, thatV I do not intend to limit myself to V@the particular details shown "or described, :except as defined in the-claims.

In the drawing:

Fig. 1 is a fragmentary top plan view'of aportion of a chamber, such as a respirator chamber, showing my improved valve applied thereto,

Fig, 2 is a fragmentary section taken on Athe line 2 2 of Fig. 1, showing the valve clampedin sealing position on the seat, and

Fig. 3 is Va fragmentary lsection taken on .the line 3-3 of Fig. l, showing the valve adjusted so -as to open a predeterminedamount upon the maximum pressure for lifting the valve r.being reached.

Referring in detail to the drawing, aportion of a chamber is shown therein, which `isfusually a respirator chamber, or chamber for receiving the body of a patient to induce breathing 4by pressure changes in said chamber. -O-nly a fragmentary portion lofthe top of the chamber is r`shown, Athe top wall 5 having an opening Btherein, which the pressure relief valve, forming the Ysubject matter of this invention, is Aadapted to close. Said valve comprises a flap member l, ywhich has a substantially circular body portion 8, and a lateral rectangular extension 9, said flap member being made of rubber or similar flexible sealing material of a compressible character.V The lat- 'eral extension 9 of said flap valve member is xed to the chamber wall 5 by any suitable securing elements, such as the headed elements l0, so as to be rmly clamped thereto. The circular body vportion 8 overlaps the opening 6 on all sides thereof, the portion of the Wall 5 surrounding the opening -6 serving as a seat for the valve.

Fastened so as to be arranged concentricallyto the circular body portion 8 of said flap valve member 1, is a reenforcingplate. Il, the `same being-shown as being secured in xed position on .the ap valve, member 'l by means `of headed Lsecurngelements I2. Thereenforcing-.plate Il serves not only as reenforcing means for the valve, but also as a Weight, which controls the pressure at which the flap valve will open. It will be noted that the weight or reeni'orcing member is of very slightly smaller diameter than the opening 6, thus tending to provide snug engagement between the compressible material of the flapjvalve` member and the edge of the seat provided at'the rim of the opening 6.

The vpressure relief accomplished by the flap valve is determined not only by the pressure at which it opens, but the amount the same opens when sufficient pressure above atmospheric pressure Within the chamber I3, of which the wall is one of the walls, has been developed. The

` amount of opening of the valve 'I is controlled by means of adjustable stop means. Said adjustable stop means comprises a yoke-like member I 4 forming a bracket, which is secured in xed position on the body portion of the chamber by securement to the wall 5, this being accomplished by welding the flanges or feet I5, provided on said yoke-like member, to said wall 5,r as clearly shown in Fig. 2. Y Said yoke-like member has a transversely extending portion I6 spaced from the wall 5, extending across the opening 6 and thus bridging the valve member 'l to protect it andto act as a mounting for the adjusting means,

.said transverse portion being spaced from the feet I5 by means of the parallel leg portions Il thereof extending away from the wall 5 connecting said feet I5 with the transverse portion I6. Said yoke-like bracket member I6 is provided with an opening I-B therein that aligns with the center of the disk-like reenforcing member Il and the center of the circular body portion 8 of the valve and the opening 5.

Secured in fixed position on the under side.

of the transverse portion I6 of said yoke-like member is a member I9, which is shown as being Welded to the transverse portion I5 of the member I4 and which is provided with an internally screw-threaded opening 2U, said member being, preferably, an ordinary nut welded to the member I6, as clearly shown in Figs. 2 and 3. screw-threaded opening 28 in said member I8 is, preferably, co-axial with the opening I8 in the member IB. Cooperating with said screwthreaded member I9 is the screw-threaded shank or stem portion 2| of the adjusting member for the valve, which is provided with means for turning the same, such as a hand wheel 22. The end 23 of the shank is adapted to be either The.

spaced from the plate II, as shown in Fig. 3,.

or in engagement therewith, as shown in Fig. 2.

By adjusting the valve to the position shown in Fig. 2, the flap valve will be held tightly closed and this will develop the maximum pressure possible above atmospheric pressure in the chamber Within'the wall 5. Adjustment of the member 2| upwardly from the position shown in Fig. 2 will, of course, increase the opening of said flap Valve when the pressure is suicient to raise the same olf its seat on the wall 5. The opening 6 can thus be sealed entirely by clamping the flap valve member down on the seat provided by the Wall 5 adjacent the opening, so that it will not open under any pressure conditions developed Within the chamber I3, When in this position `the plate I I serves as pressure distributing means to distribute the pressure evenly around the body portion of the ap valve where the same engages with the wall 5 surrounding the opening 6, and willV also serve as a wear plate, or bearing means to prevent-any wear on the valve by clamping action of the screw 2| exerted by means of the hand Wheel 22. When the valve is in a, closed position with the end 23 of the screw 2| spaced from the plate I I, the amount of opening of said valve when the pressure at which opening of the valve occurs is reached, can be denitely predetermined. A very ne adjustment of said stop member can be obtained by means of the screwthreaded connection between the stem or shank 2| and the screw-threaded member I9L Also, due to said screw-threaded connection, a self-locking stop means is provided, so that when once the stop means is adjusted, it Will remain so until again adjusted by the operator of the device and will not accidentally move out of position, so as to change the adjustment of the valve opening under pressure. A lock nut 24 for additional safety against moving the stop out of adjustment can be provided if desired.

It will be obvious from the above that a valve member that is highly capable of accomplishing the purpose of this invention is provided, which at the same time is very simple and cheap in construction and yet is sturdy and is so constructed that there is little possibility of the same being damaged in use.

What I claim is:

l. A pressure relief valve for a chamber comprising a flap member of flexible sheet material having a lateral extension secured in fixed position to a wall of said chamber adjacent an opening therein, said valve having a substantially circular body portion overlapping said opening and seating face to face on the outer face of said wail adjacent said opening to seal said opening, a disk-like metal plate slightly smaller than said opening xed substantially centrally to said body portion on the outer face thereof, a bracket fixed to said wall and having a transverse portion oiset from "said Wall, a screw-threaded stem having means thereon for rotating the same, and means on said transverse portion of said bracket provid- Ving a screw-threaded connection between said tion to a Wall of said chamber adjacent an opening therein, said valve having a--substantially circular` body portion overlapping said opening and seating face to faceV on the outer face of said wall adjacent said opening to seal said opening, a disk-like metal plate slightly smaller than said opening xed substantially centrally to said body portion on the outer face thereof, a bracket comprising a bar having a pair of end flanges fixed to said Wall, a pair of parallel portions extending from said'flanges away from said seat, and a transverse portion having an opening therein, a

member fixed to said transverse portion having a` screw-threaded opening aligning With the opening in said transverse portion, and a screwthreaded stem extending through said opening in said transverse portion and screw-threadedly engaging in said threaded opening having means thereon for rotating. the same, said stem being adjustable to move the same into clamping enchamber adjacent an opening therein, said valve having a substantially circular body portion overlapping said opening and seating face to face on the outer face of said Wall adjacent said opening to seal said opening, a disk-like metal Dlate transversely curved to substantially the curvature of the outer face of said chamber and slightly smaller than said opening xed substantially centrally to said body portion on the outer face thereof, a bracket xed to said wall and having a transverse portion offset from said wall, a screwthreaded stem having means thereon for rotating the same, and means on said transverse portion of said bracket providing a screw-threaded connection between said stem and said bracket, said stem -being adjustable to move the same into clamping engagement with said plate or into a predetermined spaced relation to said plate in the closing position of said valve to determine the amount said valve will be raised 01T its seat upon opening responsive to pressure in said chamber, said plate providing a Weight for normally seating said valve, all parts of said Valve lying externally of said chamber.

ERNEST W. CLEMENTS. 

